In a closing means for longitudinally extending hollow organs having a flexible wall and a passage, comprising at least one balloon-like chamber with a chamber volume, the chamber volume being variable by the supply of a fluid, and the passage of the hollow organ being partly or completely closable depending on the chamber volume, it is provided that a fastening device is arranged at the chamber, by which the chamber may be fastened to an outer part of the wall, parts of the wall of the hollow organ being adapted to be folded around the rectilinear chamber and to be fastened to the chamber or to each other such that the chamber, when in the fastened condition, is arranged in a fold in the wall of the hollow organ.
